介绍
什么是 Socket.IO
Socket.IO 是一个库，可以在客户端和服务器之间实现 低延迟, 双向 和 基于事件的 通信。
它建立在 WebSocket 协议之上，并提供额外的保证，例如回退到 HTTP 长轮询或自动重新连接。下面是Java版的基本示例：
示例
maven依赖
<!-- socketio -->
<dependency>
<groupId>com.corundumstudio.socketio</groupId>
<artifactId>netty-socketio</artifactId>
<version>1.7.7</version>
</dependency>
配置文件
#监听的ip(部署后设置为0.0.0.0)
socketIo.host=127.0.0.1
#监听端口
socketIo.port=10246
# 设置最大每帧处理数据的长度，防止他人利用大数据来攻击服务器
socketIo.maxFramePayloadLength=1048576
# 设置http交互最大内容长度
socketIo.maxHttpContentLength=1048576
# socket连接数大小（如只监听一个端口boss线程组为1即可）
socketIo.bossCount=1
socketIo.workCount=100
socketIo.allowCustomRequests=true
# 协议升级超时时间（毫秒），默认10秒。HTTP握手升级为ws协议超时时间
socketIo.upgradeTimeout=1000000
# Ping消息超时时间（毫秒），默认60秒，这个时间间隔内没有接收到心跳消息就会发送超时事件
socketIo.pingTimeout=6000000
# Ping消息间隔（毫秒），默认25秒。客户端向服务器发送一条心跳消息间隔
socketIo.pingInterval=25000
配置类
import com.corundumstudio.socketio.SocketConfig;
import com.corundumstudio.socketio.SocketIOServer;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
@Configuration
public class SocketIoConfig {
@Value("${socketIo.host}")
private String host;
@Value("${socketIo.port}")
private Integer port;
@Value("${socketIo.bossCount}")
private int bossCount;
@Value("${socketIo.workCount}")
private int workCount;
@Value("${socketIo.allowCustomRequests}")
private boolean allowCustomRequests;
@Value("${socketIo.upgradeTimeout}")
private int upgradeTimeout;
@Value("${socketIo.pingTimeout}")
private int pingTimeout;
@Value("${socketIo.pingInterval}")
private int pingInterval;
/**
* 以下配置在上面的application.properties中已经注明
*
* @return
*/
@Bean
public SocketIOServer socketIOServer() {
SocketConfig socketConfig = new SocketConfig();
socketConfig.setTcpNoDelay(true);
socketConfig.setSoLinger(0);
com.corundumstudio.socketio.Configuration config = new com.corundumstudio.socketio.Configuration();
config.setSocketConfig(socketConfig);
config.setHostname(host);
config.setPort(port);
config.setBossThreads(bossCount);
config.setWorkerThreads(workCount);
config.setAllowCustomRequests(allowCustomRequests);
config.setUpgradeTimeout(upgradeTimeout);
config.setPingTimeout(pingTimeout);
config.setPingInterval(pingInterval);
return new SocketIOServer(config);
}
}
SocketIoService
import com.alibaba.fastjson.JSONObject;
import com.corundumstudio.socketio.SocketIOClient;
import com.corundumstudio.socketio.SocketIOServer;
import lombok.extern.slf4j.Slf4j;
import org.springframework.stereotype.Component;
import javax.annotation.PostConstruct;
import javax.annotation.PreDestroy;
import javax.annotation.Resource;
import java.util.List;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
@Slf4j
@Component
public class SocketIoService {
/**
* 用来存已连接的客户端
*/
private static Map<String, SocketIOClient> clientMap = new ConcurrentHashMap<>();
@Resource
private SocketIOServer socketIOServer;
/**
* Spring IoC容器创建之后，在加载SocketIOServiceImpl Bean之后启动
*
* @throws Exception
*/
@PostConstruct
private void autoStartup() {
start();
}
/**
* Spring IoC容器在销毁SocketIOServiceImpl Bean之前关闭,避免重启项目服务端口占用问题
*
* @throws Exception
*/
@PreDestroy
private void autoStop() {
stop();
}
public void start() {
// 监听客户端连接
socketIOServer.addConnectListener(client -> {
String uid = getParamsByClient(client);
if (uid != null) {
clientMap.put(uid, client);
log.info("有新的客户端连接UID:{}", uid);
}
});
// 监听客户端断开连接
socketIOServer.addDisconnectListener(listener -> {
String uid = getParamsByClient(listener);
if (uid != null) {
clientMap.remove(uid);
listener.disconnect();
log.info("一条客户端连接中断");
}
});
socketIOServer.addEventListener("ServerReceive", JSONObject.class, (client, data, ackSender) -> {
String uid = getParamsByClient(client);
if (uid != null) {
log.info("接收到SID:{}发来的消息:{}", uid, data.toJSONString());
}
});
socketIOServer.start();
log.info("socket.io初始化服务完成");
}
public void stop() {
if (socketIOServer != null) {
socketIOServer.stop();
socketIOServer = null;
}
log.info("socket.io服务已关闭");
}
/**
* 此方法为获取client连接中的参数，可根据需求更改
*
* @param client
* @return
*/
private String getParamsByClient(SocketIOClient client) {
// 从请求的连接中拿出参数（这里的sid必须是唯一标识）
Map<String, List<String>> params = client.getHandshakeData().getUrlParams();
List<String> list = params.get("UID");
if (list != null && list.size() > 0) {
return list.get(0);
}
return null;
}
/**
* 推送告警信息
*
* @param jsonObject 告警信息
*/
public static void sendInfo(JSONObject jsonObject) {
for (SocketIOClient client : clientMap.values()){
client.sendEvent("alarmInfo",jsonObject);
}
}
}
前端代码
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
</head>
<body>
</body>
<script src="socket.io.js"></script>
<script type="text/javascript">
const serverUri = "http://127.0.0.1:10246/";
const sendEvent = "ServerReceive";
const receiveEvent = "alarmInfo";
var socket;
connect(uuid());
function connect(uid) {
socket = io.connect(serverUri, {
'force new connection': true,
'query': 'UID=' + uid
});
socket.on('connect', function () {
console.log("连接成功");
// 如果发送字符串send("hello Server"); *需要修改服务端接收类型
send({
name: "client",
message: "hello Server"
});
});
socket.on(receiveEvent, function (data) {
console.log(data);
});
socket.on('disconnect', function () {
console.log("连接断开");
});
}
function send(data) {
socket.emit(sendEvent, data);
}
function uuid() {
var s = [];
var hexDigits = "0123456789abcdef";
for (var i = 0; i < 36; i++) {
s[i] = hexDigits.substr(Math.floor(Math.random() * 0x10), 1);
}
s[14] = "4";
s[19] = hexDigits.substr((s[19] & 0x3) | 0x8, 1);
s[8] = s[13] = s[18] = s[23] = "-";
var uuid = s.join("");
return uuid;
}
</script>
</html>
